Two men started arguing at a Durham College/University of Ontario Institute of Technology Oshawa campus coffee shop late Wednesday afternoon, according to Durham Regional Police.
A 22-year-old male student was stabbed during the altercation. A male suspect fled from the scene.
Police received a call about the incident at about 4:30 p.m. ET.
The victim was transported to a local hospital for treatment with "serious, life-threatening injuries," according to a police statement.
The suspect is described as having brown skin, being medium build and between five feet eight inches and five feet 10 inches tall. He was wearing dark-coloured pants and a button-up dress shirt. The suspect was also carrying a backpack.
Police searched the campus, but made no arrests. Police do not believe this to be a random attack.
Anyone with information is requested to call Durham Regional Crime Stoppers at 1-800-222-TIPS (8477).